Presently, oxo process comprising synthesizing normal aldehyde by oxidation of normal paraffin and hydrogenating the obtained aldehyde is the mainstream of methods for synthesizing industrial linear alcohol. However, as the price of naphtha, raw material of normal paraffin, is escalating, the profitability is decreasing. Besides the oxo method, a method using methanol (alcohol) and synthetic gas (carbon monoxide and hydrogen) as raw materials is known. However, as carbon monoxide which is harmful is used in the method and that it is a high-pressure reaction, the plant is of a large scale and the profitability is not good. Further, Ziegler method comprising oligomerizing ethylene by trialkylaluminum, forming a long-chain aluminum alkoxide by air-oxidation, and hydrolyzing the resultant to obtain a long-chain primary alcohol is used. With that method, only alcohol having even numbers of carbon atoms having a distribution of 2-28 carbon atoms can be obtained. Moreover, a method for synthesizing 1-propanol from methanol and ethanol by Guerbet method has been proposed, while the yield is not good, as the reaction conditions are specific and thus not suitable for practical use. Furthermore, alcohol is also synthesized from plants such as copra oil (oleochemical), while only alcohol having 8 or 16 carbon atoms can be obtained, and for alcohol having other numbers of atoms, it is necessary to depend on naphtha.
As a method for synthesizing higher alcohol from methanol and ethanol, a method using ununiformed catalysts such as MgO can be exemplified (see non-patent documents 1-5, patent documents 1-4), while these methods are not suitable for industrialization as they are many side reaction products, or the reaction conditions are specific. Further, as a method for synthesizing butanol from ethanol, a method using oxidative products of alkaline-earth metals as catalysts (see non-patent document 6), a method using zeolite substituted with alkaline metal (see non-patent document 7), a method using a mixture of metal oxidative products (see non-patent document 8) can be exemplified. As for a method for manufacturing butadiene from ethanol, a method using a metal oxidative product or a mixture thereof (see non-patent documents 9-11), a method using a sepiolite catalyst which is a cellular acicular clay can be exemplified. However, these methods are not industrially suitable as the catalysts are difficult to prepare, or that the reaction temperature is high.
On the other hand, a method for synthesizing butanol, butadiene, or fuel compositions by using a hydroxyapatite catalyst (see patent documents 7, 8) has been proposed, while as it is a method using only ethanol as raw material, organic compounds that can be synthesized were limited. In other words, as ethanol is a material having 2 carbon atoms, it is not suitable for synthesizing organic compounds having odd numbers of carbon atoms, and particularly, alcohol having odd numbers of carbon atoms cannot be synthesized.
The following non-patent documents, as cited above, are incorporated herein in their entirety. Non-patent document 1: Ueda, W.; Kuwabara, T.; Ohshida, T.; Morikawa, Y. A Low-pressure Guerbet Reaction over Magnesium Oxide Catalyst. J. Chem. Soc., Chem. Commun., 1990, 1558-1559; Non-patent document 2: Ueda, W.; Ohshida, T.; Kuwabara, T.; Morikawa, Y. Condensation of alcohol over solid-base catalyst to form higher alcohols. Catal. Letters, 1992, 12, 97-104; Non-patent document 3: Olson, E. S., Sharma, R. K. and Aulich T. R. Higher-Alcohols Biorefinery Improvement of Catalyst for Ethanol Conversion. Applied Biochemistry and Biotechnology, 2004, vol. 113-116, 913-932; Non-patent document 4: Burk, P. L.; Pruett, R. L. and Campo, K. S. The Rhodium-Promoted Guerbet Reaction Part 1. Higher Alcohols from Lower Alcohols. J. of Molecular Catalysis, 1985, 33, 1-14; Non-patent document 5: Knothe, G. Synthesis, applications, and characterization of Guerbet compounds and their derivatives. Lipid Technology, 2002, September, 101-104; Non-patent document 6: “Dimerisation of ethanol to butanol over solid-base catalysts” A. S. Ndou, N. plint, N. J. Coville, Applied catalysis A: General, 251, p. 337-345 (2003); Non-patent document 7: “Bimolecular Condensation of Ethanol to 1-Butanol Catalyzed by Alkali Cation Zeolites” C. Yang, Z. Meng, J. of Catalysis, 142, p. 37-44 (1993); Non-patent document 8: “Kinetics of a Complex Reaction System-Preparation of n-Butanol from Ethanol in One Step”, V. NAGARAJAN, Indian Journal of Technology Vol. 9, October 1971, pp. 380-386; Non-patent document 9: “Butadiene from ethyl alcohol” B. B. Corson, H. E. Jones, C. E. Welling, J. A. Hincley, and E. E. Stahly, Industrial and Engineering Chemistry, Vol. 42. No. 2; Non-patent document 10: One-Step Catalytic Conversion of Ethanol to Butadiene in the Fixed Bed. I. Single-Oxide Catalysis, S. K. Bhattacharyya and N. D. Ganguly, J. Appl. Chem., 12, March 1962; Non-patent document 11: One-Step Catalytic Conversion of Ethanol to Butadiene in the Fixed Bed. II. Binary- and Ternary-Oxide Catalysis, S. K. Bhattacharyya and N. D. Ganguly, J. Appl. Chem., 12, March 1962;
The following patent documents, as cited above, are incorporated herein by reference in their entirety. Patent document 1: U.S. Pat. No. 2,971,033; Patent document 2: U.S. Pat. No. 3,972,952; Patent document 3: U.S. Pat. No. 5,300,695; Patent document 4: U.S. Pat. No. 2,050,788; Patent document 5: Japanese Laid-Open Patent Application No. 57-102822; Patent document 6: Japanese Laid-Open Patent Application No. 58-59928; Patent document 7: WO 99/38822; Patent document 8: WO2006/059729;